Catheter assembly

ABSTRACT

A catheter assembly is disclosed, which includes a catheter, a catheter hub fixed to a base end portion of the catheter, an inner needle having a needlepoint, inserted into the catheter, a needle hub coupled to the inner needle, and a needle support portion for supporting the inner needle through the catheter on a leading end side beyond the catheter hub, wherein the needle support portion has a pair of support arms openable and closeable in a left and right direction, and a restraining portion capable of restraining the pair of support arms in a closed state and releasing a restraint of the pair of support arms, the needle hub having an extension portion extending in a leading end direction beyond the catheter hub, the pair of support arms being laterally disposed between the restraining portion.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation U.S. patent application Ser. No.15/222,870 filed on Jul. 27, 2016, which is a continuation ofInternational Application No. PCT/JP2015/051776 filed on Jan. 23, 2015,which claims priority to JP 2014-014122 filed on Jan. 29, 2014, theentire content of all three of which is incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to a catheter assembly that punctures ablood vessel and is detained, for example, upon performing a transfusionto a patient.

BACKGROUND ART

Conventionally, when a transfusion is performed to a patient, forexample, a catheter assembly is used. This kind of catheter assembly caninclude a hollow catheter, a catheter hub adhered to a base end of thecatheter, an inner needle inserted into the catheter and having a sharpneedlepoint at a leading end, and a needle hub adhered to a base end ofthe inner needle. In a case where a transfusion is performed to apatient by using the catheter assembly, the catheter with the innerneedle punctures a blood vessel of the patient, and the inner needle isevulsed from the catheter while the catheter is puncturing the patientafter the puncture. Next, a connector provided at an end portion of atransfusion tube is coupled to a base end of the catheter hub, and atransfusion material is supplied into the blood vessel of the patientthrough the transfusion tube, the catheter hub, and the catheter.

It is known that a unit for supporting the inner needle through thecatheter is provided in the above catheter assembly in order to inhibitor prevent deflection of the inner needle upon the puncture (forexample, refer to JP 10-503094 W and US 2011/0282285 A).

JP 10-503094 W discloses that openable and closeable two arms extendingin a leading end direction are provided on a needle hub, and the twoarms are open before use and do not support an inner needle. A userpinches the arms upon a puncture so that the puncture can be performedwhile deflection of the inner needle is being inhibited. After thepuncture, the user weakens the pinching force with respect to the twoarms so that the two arms open and a catheter hub can move forward.

US 2011/0282285 A discloses that openable and closeable two armsextending in a leading end direction are provided on a needle hub, and,before use, the two arms have been closed, support an inner needlethrough a catheter, and have been restrained in a closed state by arestraining portion. In use, when the restraining portion moves forward,the restraint of the restraining portion is released. After that, whenthe two arms open in an upper and lower direction, a catheter hubbecomes movable forward. The two arms have been coupled to each other ata base end portion of a catheter assembly through a hinge portion.

The catheter assembly described in JP 10-503094 W requires an operationin which the user strengthens and weakens the pinching force withrespect to the two arms in order to perform support with respect to theinner needle and release from the support. Thus, the operation iscomplicated.

In the catheter assembly described in US 2011/0282285 A, since the twoarms for supporting the inner needle open in the upper and lowerdirection, a protruding length of the inner needle from the arms is madelong in order to avoid interference with skin of the patient. Thus, theinner needle easily deflects. Upon a puncture, the vicinity of leadingends of the arms in order to easily perform the puncture is held. Afterthe restraint with respect to the arms has been released, it can benecessary to hold the vicinity of base portions of the arms (a base endportion of the catheter assembly) instead of the vicinity of leadingends of the arms in order to open the arms. Thus, the operation can becomplicated.

SUMMARY OF INVENTION

A catheter assembly is disclosed, which is capable of being easilyoperated and inhibiting or preventing deflection of an inner needleeffectively upon a puncture.

A catheter assembly according to the present disclosure can include: acatheter; a catheter hub fixed to a base end portion of the catheter; aninner needle having a needlepoint, inserted into the catheter; a needlehub coupled to the inner needle; and a needle support portion forsupporting the inner needle through the catheter on a leading end sidebeyond the catheter hub. The needle support portion has a pair ofsupport arms openable and closeable in a left and right direction, and arestraining portion capable of restraining the pair of support arms in aclosed state and releasing the restraint. The needle hub has anextension portion extending in a leading end direction beyond thecatheter hub. A coupling portion between each of the pair of supportarms and the extension portion is positioned on the leading end sidebeyond a base end of the catheter hub.

With the above configuration of the present disclosure, since the pairof support arms supports the inner needle upon a puncture, thedeflection of the inner needle upon the puncture can be inhibited orprevented, and a stable puncture can be performed. In particular,according to the present disclosure, an adjustment of gripping force bya user does not perform the support of the inner needle and the releaseof the support, but a function of the restraining portion performs therestraint with respect to the pair of support arms and the release ofthe restraint. Thus, the operation is relatively simple. Since the pairof support arms that opens in the left and right direction, has nointerference with skin of a patient, there is no need for extralengthening of the inner needle in order to avoid the interference.Thus, the deflection of the inner needle can be effectively inhibited.Furthermore, since the support arms are provided on the leading end sidebeyond a base end of the catheter hub, for example, gripping theextension portion provided on the leading end side beyond the base endof the catheter hub without changing the hold of the grip, cansequentially perform a puncture operation and a forward movementoperation of the catheter hub by the same hand. Therefore, excellentoperability can be acquired.

According to an exemplary embodiment, the above catheter assembly mayfurther include: a bending first engaging groove provided in one of thesupport arms; a bending second engaging groove provided in the other ofthe support arms; a first restraining protrusion capable of engagingwith the first engaging groove, provided on the restraining portion; anda second restraining protrusion capable of engaging with the secondengaging groove, provided on the restraining portion. With thisconfiguration, the needle support portion can be constituted so as to becompact.

According to an exemplary embodiment, in the above catheter assembly,when the restraining portion is positioned at a first position, thefirst restraining protrusion may engage with the first engaging grooveand the second restraining protrusion may engage with the secondengaging groove. When the restraining portion is positioned at a secondposition, the second restraining protrusion may separate from the secondengaging groove in a state where the restraining portion has been heldby the one of the support arms, the one including the first engaginggroove. With this configuration, after the restraint with respect to thepair of support arms has been released, since the restraining portionmoves with one of the pair of support arms, a forward movement of thecatheter hub is not prevented.

According to an exemplary embodiment, in the above catheter assembly,the second restraining protrusion may protrude to a side opposite to aside on which the inner needle is present. With this configuration, whenthe one of a pair of support arms holding the restraining portion opens,the second restraining protrusion can be prevented from being hooked onthe inner needle.

According to an exemplary embodiment, in the above catheter assembly,the extension portion and each of the support arms may be coupled so asto be rotatable through a hinge structure having a first structure and asecond structure. The first structure may be provided on one of theextension portions and each of the support arms, and has a plurality ofcoupling pieces facing each other and a recess portion formed betweenthe plurality of coupling pieces. The second structure may be providedon the other of the extension portion and each of the support arms, andhas a coupling protruding portion disposed in the recess portion. Withthis configuration, since the first structure and the second structureare in relationship of the mutual engagement, unsteadiness of the hingestructure can be effectively inhibited.

According to an exemplary embodiment, in the above catheter assembly, asupport hole for supporting the inner needle may be formed between thepair of support arms in the closed state. A contact surface between thepair of support arms may be shifted in the left and right direction withrespect to a center of the inner needle supported by the support hole.With this configuration, even when force in an upper and lower directionacts on the inner needle, the inner needle barely comes off the pair ofsupport arms that has been closed.

According to an exemplary embodiment, in the above catheter assembly,the restraining portion may be slidable with respect to the pair ofsupport arms. In accordance with a forward movement of the catheter hubor a forward movement of a guide wire operating portion for operating aguide wire inserted into the inner needle, the catheter hub, a huboperating portion provided on the catheter hub, or the guide wireoperating portion may press the restraining portion so as to release therestraint with respect to the pair of support arms. With thisconfiguration, since the restraint with respect to the pair of supportarms is automatically released in response to a forward movementoperation with respect to a predetermined member, there is no need foran independent release operation. Therefore, excellent operability canbe acquired.

According to an exemplary embodiment, in the above catheter assembly,the restraining portion may be provided as a part of a hub operatingportion for operating the catheter hub or a part of a guide wireoperating portion for operating a guide wire inserted in the innerneedle. The restraint with respect to the pair of support arms may bereleased upon a forward movement of the hub operating portion or aforward movement of the guide wire operating portion. With thisconfiguration, since the restraint with respect to the pair of supportarms is automatically released in response to an operation with respectto the hub operating portion or the guide wire operating portion, thereis no need for an independent release operation. Therefore, excellentoperability can be acquired.

In accordance with an exemplary embodiment, a catheter assembly isdisclosed, comprising: a catheter; a catheter hub fixed to a base endportion of the catheter; an inner needle having a needlepoint, insertedinto the catheter; a needle hub coupled to the inner needle, the needlehub has an extension portion extending in a leading end direction beyondthe catheter hub; a needle support portion for supporting the innerneedle through the catheter on a leading end side beyond the catheterhub, the needle support portion having a pair of rotatable support arms,and a restraining portion capable of restraining the pair of supportarms; and a coupling portion between each of the pair of support armsand the extension portion is positioned on the leading end side beyond abase end of the catheter hub.

In accordance with another exemplary embodiment, a catheter assembly isdisclosed, comprising: a catheter; a catheter hub fixed to a base endportion of the catheter; an inner needle having a needlepoint, insertedinto the catheter; a needle hub coupled to the inner needle; and aneedle support portion for supporting the inner needle through thecatheter on a leading end side beyond the catheter hub, wherein theneedle support portion has a pair of support arms openable and closeablein a left and right direction, and a restraining portion capable ofrestraining the pair of support arms in a closed state and releasing arestraint of the pair of support arms, the needle hub having anextension portion extending in a leading end direction beyond thecatheter hub, the pair of support arms being laterally disposed betweenthe restraining portion.

In accordance with a further exemplary embodiment, a catheter assemblyis disclosed comprising: a catheter; a catheter hub fixed to a base endportion of the catheter; an inner needle having a needlepoint, insertedinto the catheter; a needle hub coupled to the inner needle; a needlesupport portion for supporting the inner needle through the catheter ona leading end side beyond the catheter hub, wherein the needle supportportion has a pair of support arms openable and closeable in a left andright direction, and a restraining portion capable of restraining thepair of support arms in a closed state and releasing a restraint of thepair of support arms, the needle hub having an extension portionextending in a leading end direction beyond the catheter hub, an huboperating portion coupled to the catheter hub, and the pair of supportarms being laterally disposed between the restraining portion; andwherein the restraining portion is movable with respect to the pair ofsupport arms, and a forward movement of the hub operating portionreleases the restraint with respect to the pair of support arms.

In accordance with another embodiment, a catheter assembly is disclosedcomprising: a catheter; a catheter hub configured to be fixed to a baseend portion of the catheter; an inner needle having a needlepointconfigured to be insertable into the catheter; a needle hub configuredto be coupled to the inner needle; and a needle support portionconfigured to support the inner needle through the catheter on a leadingend side beyond the catheter hub, wherein the needle support portion hasa pair of openable and closeable support arms, a restraining portioncapable of restraining the pair of openable and closeable support arms,the needle hub having an extension portion extending in a leading enddirection beyond the catheter hub, and the pair of openable andcloseable support arms being laterally disposed between the restrainingportion.

According to the catheter assembly of the present disclosure, theoperation is relatively simple and the deflection of the inner needleupon a puncture can be effectively inhibited.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a catheter assembly according to a firstembodiment of the present disclosure.

FIG. 2 is an exploded perspective view of the catheter assemblyillustrated in FIG. 1.

FIG. 3 is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 1.

FIG. 4 is a perspective view of the catheter assembly illustrated inFIG. 1 in a state where restraint with respect to a pair of support armshas been released.

FIG. 5 is a perspective view of the catheter assembly illustrated inFIG. 1 in a state where a catheter member has further moved forward fromthe state illustrated in FIG. 4.

FIG. 6 is a perspective view of the catheter assembly illustrated inFIG. 1 in a state where an inner needle has been evulsed from acatheter.

FIG. 7A is a perspective view of a needle support portion according to afirst modification.

FIG. 7B is a perspective view of a needle support portion according to asecond modification.

FIG. 8 is a perspective view of a needle support portion according to athird modification.

FIG. 9A is a perspective view of a hinge structure according to thefirst modification.

FIG. 9B is a sectional view taken along line IXB-IXB of FIG. 9A.

FIG. 9C is a perspective view of a hinge structure according to thesecond modification.

FIG. 10A is a schematic sectional view of a support hole according tothe first modification.

FIG. 10B is a schematic sectional view of a support hole according tothe second modification.

FIG. 10C is a schematic sectional view of a support hole according tothe third modification.

FIG. 10D is a schematic sectional view of a support hole according to afourth modification.

FIG. 11 is a perspective view of a catheter assembly according to asecond embodiment of the present disclosure.

FIG. 12 is an exploded view of the catheter assembly illustrated in FIG.11.

FIG. 13 is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 11.

FIG. 14 is a partially omitted rear view of the catheter assemblyillustrated in FIG. 11.

FIG. 15 is a perspective view of the catheter assembly illustrated inFIG. 11 from the rear side in a state where a first engaging portion anda first engaging protrusion have engaged with each other and a secondengaging portion and a second engaging protrusion have engaged with eachother.

FIG. 16A is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 11 in a state where a catheter hub has moved forwardpartway through.

FIG. 16B is a perspective view of the catheter assembly illustrated inFIG. 11 in the state where the catheter hub has moved forward partwaythrough.

FIG. 17A is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 11 in a state where a protector has maximallyextended.

FIG. 17B is a perspective view of the catheter assembly illustrated inFIG. 11 in the state where the protector has maximally extended.

FIG. 18 is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 11 in a state where the catheter hub and theprotector have been separated from each other.

FIG. 19 is a perspective view of a catheter assembly according to athird embodiment of the present disclosure.

FIG. 20 is an exploded perspective view of the catheter assemblyillustrated in FIG. 19.

FIG. 21 is a partially omitted longitudinal-sectional view of thecatheter assembly illustrated in FIG. 19.

FIG. 22A is a perspective view of a coupling state between a catheterhub and a hub operating portion.

FIG. 22B is a perspective view of a separating state between thecatheter hub and the hub operating portion.

FIG. 23 is a cross-sectional view taken along line XXIII-XXIII of FIG.21.

FIG. 24A is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 19 in a state where the hub operating portion hasmoved slightly forward.

FIG. 24B is a perspective view of a part of the catheter assembly in thestate of FIG. 24A.

FIG. 25 is a longitudinal-sectional view of a state where the huboperating portion has further moved forward from the state of FIG. 24A.

FIG. 26 is a longitudinal-sectional view of a state where the huboperating portion has further moved forward from the state of FIG. 25and a protector has maximally extended.

FIG. 27 is a longitudinal-sectional view of the catheter assemblyillustrated in FIG. 19 in a state where a catheter member and theprotector have separated from each other.

DETAILED DESCRIPTION

Preferred embodiments regarding a catheter assembly according to thepresent disclosure, will be given and described below with reference tothe drawings.

FIG. 1 is a perspective view of an entire configuration of a catheterassembly 10A according to a first embodiment of the present disclosure.FIG. 2 is an exploded perspective view of the catheter assembly 10A.FIG. 3 is a longitudinal-sectional view of the catheter assembly 10A.

The catheter assembly 10A can include a tubular catheter 12 functioningas an outer needle, a catheter hub 14 coupled to the side of a base endof the catheter 12, a tubular inner needle 16 having a sharp needlepoint17 at a leading end and insertable into the inside of the catheter 12, aneedle hub 18 coupled to the inner needle 16, and a needle supportportion 20 for inhibiting or preventing deflection of the inner needle16 upon a puncture.

With the catheter assembly 10A, a user (for example, a medical doctor ora nurse) grips and operates the needle hub 18 so that a leading endportion of the needle hub 18 punctures a blood vessel of a patient. Thecatheter assembly 10A has a double tubular structure in which the innerneedle 16 has been inserted into the catheter 12 and the inner needle 16has protruded from a leading end of the catheter 12 by a predeterminedlength in an initial state before use (before a puncture to thepatient).

The catheter assembly 10A in the initial state can include one assemblyhaving the double tubular structure of the catheter 12 and the innerneedle 16, the catheter hub 14, the needle hub 18, and the needlesupport portion 20 combined, and is integrally operable.

The catheter 12 is a tubular member that has been formed so as to have apredetermined length, with a small diameter and flexibility. A resinmaterial and, in particular, a soft resin material are preferable asexamples of a constituent material of the catheter 12. In this case, forexample, fluororesins, such as polytetrafluoroethylene (PTFE),ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoroalkoxyfluoropolymer (PFA), olefin resins, such as polyethylene andpolypropylene, or a mixture thereof, polyurethane, polyester, polyamide,polyether nylon resin, and a mixture of the olefin resin andethylene-vinyl acetate copolymer, are provided. The catheter 12 mayinclude a resin having transparency so that the entire or partial insideof the catheter can be visually ascertained.

The catheter hub 14 is coupled and fixed to the base end of the catheter12. A flange portion 22 protruding outward and extending in acircumferential direction, is provided on a base end of the catheter hub14. A cutout 23 is provided on each of the right side and the left sideof the flange portion 22.

The catheter hub 14 is provided with a hub operating portion 24 foroperating the catheter hub 14. As illustrated in FIG. 1, the huboperating portion 24 of the present illustrated example is a tabprotruding upward from a leading end of the catheter hub 14, and can beintegrally formed with respect to the catheter hub 14. The hub operatingportion 24 may be constituted as a component separated from the catheterhub 14, and may be attachable to and detachable from the catheter hub 14In accordance with an exemplary embodiment, the user touches and gripsor presses the hub operating portion 24 so that the catheter hub 14 canbe operated in an axial direction. Note that a position at which the huboperating portion 24 is provided is not limited to the leading end ofthe catheter hub 14, and may be provided between the leading end and thebase end of the catheter hub 14.

Hereinafter, a member including the catheter 12, the catheter hub 14,and the hub operating portion 24, will be referred to as a “cathetermember 25”.

Upon the use of the catheter assembly 10A, the catheter hub 14 isexposed on skin of the patient, stuck, and detained on the skin with adressing material or a tape in a state where the catheter 12 haspunctured the blood vessel. The above catheter hub 14 preferably caninclude a material harder than the catheter 12. Examples of theconstituent material of the catheter hub 14 that can be preferably usedinclude, but are not particularly limited to, thermoplastic resins, suchas polypropylene, polycarbonate, polyamide, polysulfone, polyarylate,and methacrylate-butylene-styrene copolymer.

The inner needle 16 is a tubular member having rigidity capable ofpuncturing the skin of the patient in FIGS. 1 and 2. The inner needle 16is formed sufficiently longer than the catheter 12. In the initial stateof the catheter assembly 10A, the needlepoint 17 protrudes from aleading end opening of the catheter 12 by a predetermined length. Inaddition, in the initial state, the inner needle 16 has a midway part inthe longitudinal direction inserted into the inside of the catheter hub14, and has the side of the base end held by the needle hub 18.

Examples of a constituent material of the inner needle 16 include metalmaterials, such as stainless steel, aluminum or an aluminum alloy,titanium or a titanium alloy.

The needle hub 18 has a hub body 36 disposed in series with the catheterhub 14 and an extension portion 38 extending from the hub body 36 in aleading end direction in the initial state. The hub body 36 has an innerneedle holding portion 39 that fixes and holds a base end portion of theinner needle 16.

According to the present embodiment, a pair of extension portions 38faces each other along the inner needle 16 over both sides of the innerneedle 16 and the catheter hub 14, one of the pair of extension portions38 being provided on the right side of the hub body 36, the other beingprovided on the left side of the hub body 36. The extension portions 38extend to the leading end side beyond the base end of the catheter hub14 in the initial state of the catheter hub 14. That is, leading ends ofthe extension portions 38 are positioned on the leading end side beyondthe leading end of the catheter hub 14. The extension portions 38 areformed so as to be appropriate in size (thickness, length). Thus, theuser can easily grip and operate the catheter assembly 10A upon the useof the catheter assembly 10A.

An inside surface of each of the pair of extension portions 38 facingeach other can include a guide protrusion 40 extending in an axialdirection of the inner needle 16 provided thereon. The left and rightguide protrusions 40 are inserted into the left and right cutouts 23provided on the flange portion 22 of the catheter hub 14, respectively.Accordingly, the catheter hub 14 is stably supported by the needle hub18 in the initial state. In addition, rotation of the catheter hub 14with respect to the needle hub 18 can be prevented so that the huboperating portion 24 can be held upward. Upon moving the catheter hub 14forward with respect to the needle hub 18, the catheter hub 14 can besmoothly moved forward and operated due to a guide function of the guideprotrusions 40.

Next, the needle support portion 20 will be described. The needlesupport portion 20 supports the inner needle 16 through the catheter 12on the leading end side beyond the catheter hub 14 in the initial stateof the catheter assembly 10A. The needle support portion 20 is providedmovable with respect to the needle hub 18 in order to change from afirst state of supporting the inner needle 16 to a second state ofreleasing the support with respect to the inner needle 16 and allowingthe catheter hub 14 to pass.

According to the present embodiment, specifically, the needle supportportion 20 has a pair of support arms 42 openable and closeable and arestraining portion 44 capable of restraining the pair of support arms42 in a closed state and also releasing the restraint. Hereinafter, in acase where one and the other of the pair of support arms 42 aredistinguished from each other and described, the one will be indicatedas a “support arm 42 a” and the other will be indicated as a “supportarm 42 b”.

Each of the pair of support arms 42 is rotatably coupled to each of theextension portions 38 through each of a pair of support pins 43. In thepresent illustrated example, each of the pair of support pins 43 has anaxis in an upper and lower direction. The pair of support arms 42supported by the pair of support pins 43 is openable and closeable in aleft and right direction. In the initial state, a coupling portionbetween each of the pair of support arms 42 and each of the pair ofextension portions 38, is positioned on the leading end side beyond thebase end of the catheter hub 14.

Each of the extension portions 38 and each of the support arms 42 arecoupled so as to be rotatable through a hinge structure 48 having afirst structure 45 and a second structure 46. According to the presentembodiment, the first structure 45 is provided at a leading end of eachof the extension portions 38 and the second structure 46 is provided ata base end of each of the support arms 42. The first structure 45 has aplurality of coupling pieces 49 spaced apart in the upper and lowerdirection and facing each other, and a recess portion 50 formed betweenthe plurality of coupling pieces 49. The second structure 46 has acoupling protruding portion 51 disposed in the recess portion 50. Thesupport pin 43 is inserted into the coupling protruding portion 51 andthe two coupling pieces 49 on each of the left side and the right side.Note that, according to a modification, the first structure 45 may beprovided at the base end of each of the support arms 42 and the secondstructure 46 may be provided at the leading end of each of the extensionportions 38.

Each of the support arms 42 has a support groove 53 for holding theinner needle 16 in a state where the pair of support arms 42 has beenclosed, provided thereon. In the state where the pair of support arms 42has been closed, the two support grooves 53 form a support hole 54 forsupporting the inner needle 16 (inner needle 16 inserted into thecatheter 12). In the initial state of the catheter assembly 10A, thesupport hole 54 extends in a direction in which the inner needle 16extends.

In accordance with an exemplary embodiment, one of the support arms 42has a bending engaging groove 56 a provided thereon and the other has abending engaging groove 56 b provided thereon when viewed from the frontside in the closed state. Each of the engaging grooves 56 a and 56 bpasses through each of the support arms 42 in a longitudinal direction.The one engaging groove 56 a (hereinafter, referred to as a “firstengaging groove 56 a”) and the other engaging groove 56 b (hereinafter,referred to as a “second engaging groove 56 b) mutually bend in oppositedirections. In accordance with an exemplary embodiment, the firstengaging groove 56 a bends downward and the second engaging groove 56 bbends upward.

Note that, as illustrated in FIG. 3, in a case where a puncture at asmall angle is performed to a skin S of a patient, a lower portion ofeach of the support arms 42 may be at least trimmed so that the supportarms 42 does not interfere with the skin S.

The restraining portion 44 is disposed slidable with respect to the pairof support arms 42. The restraining portion 44 is pressed by thecatheter hub 14 in accordance with a forward movement of the catheterhub 14 so that the restraint with respect to the pair of the supportarms 42 is released.

In accordance with an exemplary embodiment, the restraining portion 44has a first restraining protrusion 58 a engaging with the first engaginggroove 56 a so as to be slidable and a second restraining protrusion 58b engaging with the second engaging groove 56 b so as to be slidable. Inthe present illustrated example, the first restraining protrusion 58 aand the second restraining protrusion 58 b mutually protrude in oppositedirections so as to fit to shapes of the first engaging groove 56 a andthe second engaging groove 56 b provided on the pair of support arms 42,respectively. When the restraining portion 44 is positioned at aninitial position (a backward position), the first restraining protrusion58 a and the second restraining protrusion 58 b of the restrainingportion 44 engage with the first engaging groove 56 a and the secondengaging groove 56 b of the pair of support arms 42, respectively.Accordingly, the pair of support arms 42 is restrained in the closedstate.

The second restraining protrusion 58 b separates from the secondengaging groove 56 b of the other of a pair of support arms 42 in theleading end direction in accordance with a movement of the restrainingportion 44 in the leading end direction. When the second restrainingprotrusion 58 b separates from the second engaging groove 56 b, therestraint of the restraining portion 44 with respect to the pair ofsupport arms 42 is released and the pair of support arms 42 becomesexpansible. Note that, even after the second restraining protrusion 58 bhas separated from the second engaging groove 56 b, engagement betweenthe first restraining protrusion 58 a and the first engaging groove 56 ais retained so that the restraining portion 44 is held by the supportarm 42 a.

In a state where the second restraining protrusion 58 b has separatedfrom the second engaging groove 56 b, the second restraining protrusion58 b protrudes to the side opposite to the side on which the innerneedle 16 is present (refer to FIG. 4). Accordingly, when the supportarms 42 open in a state where the inner needle 16 has bended to the sideof the restraining portion 44, the inner needle 16 is prevented frombeing hooked on the second restraining protrusion 58 b. Note that,according to a modification, the second restraining protrusion 58 b mayprotrude to the side on which the inner needle 16 is present. In thiscase, a bending shape of the second engaging groove 56 b to be providedto the support arm 42 b, is formed so as to be in a direction in whichthe second restraining protrusion 58 b protrudes.

A base end of the restraining portion 44 can include a portion to bepressed 60 provided thereat. Upon a forward movement of the catheter hub14 with respect to the needle hub 18, the leading end of the catheterhub 14 pressed the portion to be pressed 60 so that the restrainingportion 44 moves forward with respect to the pair of support arms 42. Asurface of the portion to be pressed 60 facing the catheter hub 14 caninclude a taper that inclines so as to be displaced outward in the leftand right direction as going in a base end direction, provided thereon.

The catheter assembly 10A according to the first embodiment is basicallyconstituted as described above. Functions and effects of the catheterassembly 10A will be described below.

As illustrated in FIGS. 1 and 3, the catheter assembly 10A in theinitial state is in a state to be described below. The inner needle 16has been inserted into the catheter 12 and the needlepoint 17 hasprotruded from the leading end of the catheter 12 by the predeterminedlength. The catheter hub 14 has been positioned on the side of a baseend so as to be maximum with respect to the needle hub 18. One of theextension portions 38 is present on the right side of the catheter hub14 and the other of the extension portions 38 is present on the leftside. The side of a leading end of the inner needle holding portion 39of the needle hub 18 has been inserted into the base end of the catheterhub 14. The restraining portion 44 has been positioned at the backwardposition in a movable range. The pair of support arms 42 has beenrestrained in the closed state by the restraining portion 44. The innerneedle 16 has been held by the pair of support arms 42 in the closedstate through the catheter 12.

In the use of the catheter assembly 10A, a user (for example, a medicaldoctor or a nurse) grips the needle hub 18 and punctures a blood vesselof a patient with the catheter 12 and the inner needle 16. In this case,the inner needle 16 has been supported by the support hole 54 formedbetween the pair of support arms 42 in the closed state, through thecatheter 12, so that deflection of the inner needle 16 is inhibited uponthe puncture. Accordingly, a stable puncture can be performed relativelyeasily.

After the puncture, a finger hooks the hub operating portion 24protruding upward from the catheter hub 14, and presses the huboperating portion 24 in the leading end direction. Accordingly, thecatheter hub 14 and the catheter 12 that have been coupled to the huboperating portion 24, move in the leading end direction with respect tothe needle hub 18. Thus, an insertion length of the catheter 12 into theblood vessel increases.

As illustrated in FIG. 4, the hub operating portion 24 presses therestraining portion 44 in the leading end direction in accordance withthe forward movement of the catheter hub 14. Accordingly, therestraining portion 44 moves in the leading end direction with respectto the pair of support arms 42, and the second restraining protrusion 58b separates from the second engaging groove 56 b. The second restrainingprotrusion 58 b separates from the second engaging groove 56 b so thatthe restraint of the restraining portion 44 with respect to the pair ofsupport arms 42 is released and the pair of support arms 42 becomesexpansible.

After that, when the catheter hub 14 further moves forward, the pair ofsupport arms 42 is pressed from the rear side by the hub operatingportion 24 and the catheter hub 14 and expands as illustrated in FIG. 5.In this manner, the needle support portion 20 supports the inner needle16 in the initial state so as to inhibit the deflection of the innerneedle 16 upon the puncture. Meanwhile, after the puncture, the pair ofsupport arms 42 opens so as to prevent interference with the catheterhub 14.

After the catheter 12 has been inserted into the blood vessel by apredetermined length, the needle hub 18 is next pulled in the base enddirection in a state where a position of the catheter member 25 has beenheld. Accordingly, the inner needle 16 moves in the base end directioninside the catheter member 25. The inner needle 16 is shortly andcompletely evulsed from the catheter member 25 as illustrated in FIG. 5.As a result, a state where only the catheter member 25 out of thecatheter assembly 10A has been detained on the side of the patient, canbe acquired.

After the inner needle 16 has been evulsed from the catheter member 25,the catheter hub 14 is fixed to the patient with, for example, adressing material or a tape. A connector of a transfusion tube, notillustrated, is coupled to the side of the base end of the catheter hub14, and supply of a transfusion material (for example, a medical fluid)to the patient through the transfusion tube is performed.

As described above, the catheter assembly 10A according to the firstembodiment is capable of inhibiting the deflection of the inner needle16 upon a puncture and performing a stable puncture since the pair ofsupport arms 42 supports the inner needle 16 upon the puncture.

In accordance with an exemplary embodiment, according to the presentdisclosure, an adjustment of gripping force by the user does not performthe support of the inner needle 16 and the release of the support, butthe function of the restraining portion 44 performs the restraint withrespect to the pair of support arms 42 and the release of the restraint.Thus, the operation is relatively simple.

Since the pair of support arms 42 that opens in the left and rightdirection has no interference with the skin S of the patient, there isno need for extra lengthening the inner needle 16 in order to avoid theinterference. Thus, the deflection of the inner needle 16 can beeffectively inhibited.

Furthermore, since the support arms 42 are provided on the leading endside beyond the base end of the catheter hub 14, for example, grippingthe extension portions 38 provided on the leading end side beyond thebase end of the catheter hub 14 without changing the hold of the grip,can sequentially perform a puncture operation and a forward movementoperation of the catheter hub 14 by the same hand. Therefore, excellentoperability can be acquired.

In accordance with an exemplary embodiment, according to the firstembodiment, since the restraint with respect to the pair of support arms42 is automatically released in response to a forward movement operationwith respect to the hub operating portion 24, there is no need for anindependent release operation. Therefore, excellent operability can beacquired.

According to the first embodiment, a structure is disclosed in which thefirst and second restraining protrusions 58 a and 58 b provided on therestraining portion 44 engage with the first and second engaging grooves56 a and 56 b provided on the pair of support arms 42, respectively.Therefore, the needle support portion 20 can be constituted so as to becompact.

Furthermore, according to the first embodiment, when the restrainingportion 44 has been positioned at a forward movement position, thesecond restraining protrusion 58 b separates from the second engaginggroove 56 b in a state where the restraining portion 44 has been held bythe support arm 42 a including the first engaging groove 56 a providedthereon. With this configuration, since the restraining portion 44 moveswith one of the pair of support arms 42 after the restraint with respectto the pair of support arms 42 has been released, the forward movementof the catheter hub 14 is not prevented.

In accordance with an exemplary embodiment, since the second restrainingprotrusion 58 b protrudes in the side opposite to the side on which theinner needle 16 is present, when the one of the pair of support arm 42 athat holds the restraining portion 44 opens, the second restrainingprotrusion 58 b can be prevented from being hooked on the inner needle16.

According to the first embodiment, each of the extension portions 38 andeach of the support arms 42 are coupled so as to rotatable through thehinge structure 48 having the first structure 45 and the secondstructure 46. The first structure 45 and the second structure 46 are inrelationship of the mutual engagement. Thus, unsteadiness of the hingestructure 48 can be inhibited.

In accordance with an exemplary embodiment, in the above configuration,the hub operating portion 24 presses the restraining portion 44 so thatthe restraint with respect to the pair of support arms 42 is released.Instead of this type of configuration, the catheter hub 14 may press therestraining portion 44 so that the restraint with respect to the pair ofsupport arms 42 may be released. Alternatively, the catheter assembly10A may further include a guide wire G inserted into the inner needle 16and a guide wire operating portion 64 for operating the guide wire G,the guide wire operating portion 64 being coupled to the guide wire G(refer to FIG. 3). In this case, the guide wire operating portion 64 maypress the restraining portion 44 in accordance with a forward movementof the guide wire operating portion 64. Thus, the restraint with respectto the pair of support arms 42 may be released.

Instead of the above needle support portion 20, needle support portions20 a to 20 c illustrated in FIGS. 7A to 8 may be adopted. Note that theillustrations of the inner needle 16, the catheter 12, and the catheterhub 14 have been omitted in FIGS. 7A to 8.

The needle support portion 20 a illustrated in FIG. 7A can include apair of support arms 65 slidable in a left and right direction withrespect to left and right extension portions 38, provided therein. Inthis case, each of the extension portions 38 has a slide hole 38 a forholding each of the support arms 65 to be slidable in the left and rightdirection, provided therein, for example. With the above configurationin FIG. 7A, the pair of support arms 65 is also openable and closeablein the left and right direction. Therefore, a first state where theinner needle 16 has been supported can change to a second state wherethe support of the inner needle 16 has been released and the catheterhub 14 has been allowed to pass.

A needle support portion 20 b illustrated in FIG. 7B can include a pairof support arms 66 that has been supported so as to be rotatable by apair of support pins 67 parallel to the axial direction of the innerneedle 16. In this case, for example, leading ends of left and rightextension portions 38 cam be coupled together, and the pair of supportpins 67 is fixed to the coupled portion 38 b. With the aboveconfiguration in FIG. 7B, the pair of support arms 66 is also openableand closeable in the left and right direction. Therefore, a first statewhere the inner needle 16 has been supported can change to a secondstate where the support of the inner needle 16 has been released and thecatheter hub 14 has been allowed to pass.

A needle support portion 20 c illustrated in FIG. 8 can include a pairof support arms 68 openable and closeable in the left and rightdirection, and a restraining portion 69 capable of restraining the pairof support arms 68 in a closed state and releasing the restraint. InFIG. 8, the restraining portion 69 is formed so as to have a frame shapesurrounding leading end portions of the support arms 68, and is capableof restraining the pair of support arms 68 in a closed state. Instead ofthe hub operating portion 24, a hub operating portion 24 a is provided.The hub operating portion 24 a is coupled to the restraining portion 69.When a forward movement operation of the hub operating portion 24 a isperformed, the restraining portion 69 separates from the pair of supportarms 42 in the leading end direction. Thus, the restraint with respectto the pair of support arms 68 is released. Note that, instead of thehub operating portion 24 a, a guide wire operating portion may beprovided.

Note that, with the configuration in FIG. 8, the restraining portion 69has been formed so as to have the frame shape surrounding the leadingend portions of the support arms 68. Left and right inward protrudingends 69 a of the restraining portion 69 enter step portions 68 aprovided at leading end lower portions of the support arms 68. Due tothe above configuration, a structure present below the inner needle 16can be prevented from increasing in size. In contrast, in a case wherethe step portions 68 a that the left and right inward protruding ends 69a of the restraining portion 69 enter are not provided on the supportarms 68, a structure present below the inner needle 16 increases in sizeand easily interfere with skin of a patient.

Instead of the above hinge structure 48, a hinge structure 48 aillustrated in FIGS. 9A and 9B may be adopted. Note that FIG. 9B is asectional view taken along line IXB-IXB of FIG. 9A. In the hingestructure 48 a, a support arm 42 and an extension portion 38 areintegrally formed through a thin-walled portion 70. In this case, thethin-walled portion 70 functions as a bending portion so that thesupport arm 42 is rotatable with respect to the extension portion 38.

As a hinge structure 48 b illustrated in FIG. 9C, a configuration inwhich one coupling piece 71 provided at a base end of a support arm 42and one coupling piece 72 provided at a leading end of an extensionportion 38 are coupled with a support pin 43 so as to be rotatable in astate where vertically overlapping with each other, may be adopted.Alternatively, the hinge structure 48 b may have a configuration inwhich the support pin 43 and the support arm 42 have been integrallyformed. Instead of using the support pin 43, a configuration in whichthe support arm 42 and the extension portion 38 have been integrallyformed through a thin-walled portion, may be provided.

In the above configuration, each of the support arms 42 can include thesupport groove 53 provided thereon, and the two support grooves 53 formthe support hole 54. Thus, a position of a contact surface between thesupport arms 42 in the left and right direction is substantially thesame as a position of an axis of the inner needle 16 supported by thesupport hole 54. Accordingly, in a case where predetermined force ormore acts on the inner needle 16 in the upper and lower direction, thereis a possibility that the inner needle 16 comes off the pair of supportarms 42 that has been closed. Therefore, instead of the support hole 54,for example, support holes 54 a to 54 d illustrated in FIGS. 10A to 10D,respectively, may be adopted. Note that, FIGS. 10A to 10D schematicallyillustrate the restraining portion 44 and the first and second engaginggrooves 56 a and 56 b have been omitted in order to mainly exemplifystructures of the support holes 54 a to 54 d.

The structure of the support hole 54 a illustrated in FIG. 10A caninclude no support groove provided on one support arm 42 a and a supportgroove 53 a (a groove deeper than the support groove 53) provided ononly the other support arm 42 b. In a state where the pair of supportarms 42 has been closed, an inner surface of the one support arm 42 aand the support groove 53 a provided on the other support arm 42 b formthe support hole 54 a. With this structure, a position of a contactsurface between the pair of support arms 42 moves in the left and rightdirection with respect to the center of the inner needle 16 supported bythe support hole 54 a. Accordingly, even when force in the upper andlower direction acts on the inner needle 16, the inner needle 16 barelycomes off the pair of support arms 42 that has been closed.

The structure of the support hole 54 b illustrated in FIG. 10B caninclude a protruding portion 73 protruding inward (the side of the othersupport arm 42 b), provided on one support arm 42 a, and a supportgroove 53 b further deep provided on the other support arm 42 b. In acase where the pair of support arms 42 has been closed, the protrudingportion 73 is inserted into the support groove 53 b, and the protrudingportion 73 and the support groove 53 b form the support hole 54 b. Withthis structure, a position of a contact surface between the pair ofsupport arms 42 also moves in the left and right direction with respectto the center of the inner needle 16 supported by the support hole 54 b.Thus, the inner needle 16 barely comes off.

The structure of the support hole 54 c illustrated in FIG. 10C caninclude step portions 74 and 75 provided on an inner surface of onesupport arm 42 a. In a state where a pair of support arms 42 has beenclosed, the left and right step portions 74 and 75 form the support hole54 c. With this structure, a position of a contact surface between thepair of support arms 42 also moves in the left and right direction withrespect to the center of the inner needle 16 supported by the supporthole 54 c. Thus, the inner needle 16 barely comes off.

The structure of the support hole 54 d illustrated in FIG. 10D caninclude stair-shapes 76 and 77 having multiple steps provided onrespective inner surfaces of support arms 42. In a state where the pairof support arms 42 has been closed, the left and right stair-shapes 76and 77 form the support hole 54 d. With this structure, a position of acontact surface between the pair of support arms 42 also moves in theleft and right direction with respect to the center of the inner needle16 supported by the support hole 54 d. Thus, the inner needle 16 barelycomes off.

FIG. 11 is a perspective view of a catheter assembly 10B according to asecond embodiment of the present disclosure. FIG. 12 is an explodedperspective view of the catheter assembly 10B. FIG. 13 is alongitudinal-sectional view of the catheter assembly 10B. Note that, inthe catheter assembly 10B according to the second embodiment, elementshaving functions and effects the same as or similar to those of thecatheter assembly 10A according to the first embodiment, are denotedwith the same reference signs, and the duplicate descriptions thereofwill be omitted.

The catheter assembly 10B can include a tubular catheter 82 havingflexibility, a catheter hub 84 coupled to the side of a base end of thecatheter 82, a tubular inner needle 86 having a sharp needlepoint 87 ona leading end and insertable into the inside of the catheter 82, aneedle hub 88 coupled to the inner needle 86, a protector 90 that coversthe needlepoint 87 of the inner needle 86 when the inner needle 86 isevulsed, and a needle support portion 20 for inhibiting deflection ofthe inner needle 86.

With the catheter assembly 10B, a user (for example, a medical doctor ora nurse) grips and operates the needle hub 88 so that a leading endportion of the needle hub 88 punctures a blood vessel of a patient. Thecatheter assembly 10B has a double tubular structure in which the innerneedle 86 has been inserted into the catheter 82 and the inner needle 86has protruded from a leading end of the catheter 82 by a predeterminedlength in an initial state before use (before a puncture to thepatient). In the initial state of the catheter assembly 10B, thecatheter hub 84 and the needle hub 88 have been coupled through theprotector 90.

The catheter assembly 10B in the initial state can include one assemblyhaving the double tubular structure of the catheter 82 and the innerneedle 86, the catheter hub 84, the protector 90, and the needle hub 88combined, and is integrally operable.

The hollow cylindrical catheter hub 84 is coupled and fixed to the baseend of the catheter 82. A flange portion 92 protruding outward andextending in a circumferential direction, is provided on a base end ofthe catheter hub 84.

The catheter hub 84 can include a pair of wings 94 that protrudes in aleft and right direction in a natural state, provided thereon. The wings94 each have flexibility and are foldable so as to overlap with eachother. As illustrated in FIG. 12, according to the present embodiment,each of the wings 94 can include a first thin-walled portion 95 providedat a coupling part with the catheter hub 84 and a second thin-walledportion 96 provided on the outside beyond the first thin-walled portion95. The first thin-walled portion 95 is provided so as to begroove-shaped on the side of a lower surface of each of the wings 94.The second thin-walled portion 96 is provided so as to be groove-shapedon the side of an upper surface of each of the wings 94.

With this configuration, the wings 94 can easily fold upward at parts ofthe first thin-walled portions 95 and can easily fold in a directionopposite to the first thin-walled portions 95 at parts of the secondthin-walled portions 96. As illustrated in FIG. 11, in the initial stateof the catheter assembly 10B, outer end portions of the wings 94 areexposed from the needle hub 88. The user touches and grips or pressesthe wings 94 exposed from the needle hub 88 so that the catheter hub 84can be operated in an axial direction. That is, the pair of wings 94functions as an operating portion for operating the catheter hub 84.

Hereinafter, a member including the catheter 82, the catheter hub 84,and the pair of wings 94, will be referred to as a “catheter member 98.”

As illustrated in FIG. 13, the inner needle 86 is formed sufficientlylonger than the catheter 82. In the initial state of the catheterassembly 10B, the needlepoint 87 protrudes from a leading end opening ofthe catheter 82 by a predetermined length. In addition, in the initialstate, the inner needle 86 has a midway part in the longitudinaldirection inserted into the inside of the catheter hub 84, and has theside of the base end held inside the needle hub 88.

As illustrated in FIGS. 12 and 13, the needle hub 88 has an inner needleholding portion 101 holding the base end of the inner needle 86, and anextension portion 100 protruding in a leading end direction beyond thecatheter hub 84. The extension portion 100 is included in a housing thathouses the catheter hub 84 and the protector 90 in the initial state.

The inner needle holding portion 101 protrudes downward from the centerin the left and right direction on the side of a base end of theextension portion 100. A rail groove 102 extending in the axialdirection is provided on each of left and right inside surfaces of theextension portion 100.

In the initial state of the catheter assembly 10B, the catheter 82 andthe inner needle 86 are exposed from a leading end of the needle hub 88,and the catheter hub 84 and the protector 90 are housed in the needlehub 88. As a result, the leading end of the needle hub 88 protrudes to amidway of the catheter 82. According to the present embodiment, aposition of the base end of the catheter hub 84 is positioned on thebase end side beyond a position of the center in an axial direction ofthe needle hub 88, and the leading end of the needle hub 88 ispositioned on the leading end side beyond a position of the center in alongitudinal direction of the catheter 82.

As illustrated in FIGS. 11 to 13, a slit 103 that extends in the axialdirection of the needle hub 88 and is open on the side of the leadingend of the needle hub 88, is formed in the needle hub 88 (specifically,the extension portion 100). According to the present embodiment, theslit 103 can be formed on an upper wall of the needle hub 88. In theinitial state of the catheter assembly 10B, the outer end portions ofthe wings 94 that have been folded and overlap each other protrudeupward from the needle hub 88 through the slit 103.

The protector 90 houses the inner needle 86 in accordance with evulsionof the inner needle 86 from the catheter 82 so as to cover theneedlepoint 87 of the inner needle 86. As illustrated in FIGS. 12 and13, the protector 90 has an inner tube 104 fitting to the base end ofthe catheter hub 84 so as to be separable, and an outer tube 106 inwhich the inner tube 104 is disposed on the inside of the outer tube106, and which is relatively displaceable in the axial direction in arange regulated with respect to the inner tube 104. Upon the evulsion ofthe inner needle 86 from the catheter 82, the protector 90 extends so asto cover an entire length of the inner needle 86 (refer to FIG. 18).

The inner tube 104 functions to cover the needlepoint 87 of the innerneedle 86 in accordance with the evulsion of the inner needle 86 fromthe catheter 82. The inner tube 104 has a body portion 107 and a leadingend fitting portion 108 protruding from the body portion 107 in theleading end direction. An upper wall of the body portion 107 can includea cutout 109 extending in the axial direction, formed thereon. In theinitial state, the inner tube 104 is positioned in the base end of theneedle hub 88. The inner needle holding portion 101 of the needle hub 88is inserted into the cutout 109 of the body portion 107. Each of leftand right outer surfaces of the body portion 107 can include a railprotrusion 110 extending in the axial direction (refer to FIG. 12)provided thereon.

The leading end fitting portion 108 of the inner tube 104 is formed soas to have a taper shape that decreases in outer diameter as going inthe leading end direction. In the initial state, the leading end fittingportion 108 of the inner tube 104 fits into the base end of the catheterhub 84. The inner tube 104 and the catheter hub 84 are coupled due tofrictional resistance on a fitting surface.

The outer tube 106 is disposed between the inner tube 104 and the needlehub 88. An upper wall of the outer tube 106 can include a cutout 112extending in the axial direction, formed thereon. In the initial state,the outer tube 106 is positioned in the base end of the needle hub 88with the inner tube 104. The inner needle holding portion 101 of theneedle hub 88 is inserted into the cutout 112.

A rail groove 117 extending in the axial direction is provided on eachof left and right inner surfaces of the outer tube 106. The railprotrusions 110 provided on the inner tube 104 are inserted into therail grooves 117 provided on the outer tube 106 (refer to FIG. 15). Eachof left and right outer surfaces of the outer tube 106 can include arail protrusion 118 extending in the axial direction provided thereon.The rail protrusions 118 provided on the outer tube 106 are insertedinto the rail grooves 102 provided on the extension portion 100 (referto FIG. 15).

As illustrated in FIG. 12, an outer surface of a base end portion of theinner tube 104 can include a first engaging protrusion 120 protrudingoutward (downward in the illustrated example) provided thereon.Meanwhile, as illustrated in FIGS. 14 and 15, the outer tube 106 caninclude a first passage 121 extending in the axial direction andallowing the first engaging protrusion 120 to be displaced in the axialdirection, and a first engaging portion 122 disposed on the side of alead end of the first passage 121, provided thereon. The first passage121 extends to a base end surface of the outer tube 106. In the initialstate of the catheter assembly 10B, the first engaging protrusion 120 ispositioned at a base end of the first passage 121. According to thepresent embodiment, the first passage 121 is a hole passing through theinside and the outside of the outer tube 106, but may be a grooveprovided on an inner surface of the outer tube 106.

The first engaging portion 122 has a pair of pawls 123 protruding intothe first passage 121. A slit long hole 124 extending in the axialdirection of the outer tube 106, is provided on each of the left andright outsides of the pair of pawls 123. Accordingly, the pair of pawls123 is elastically deformable in directions in which the pair of pawls123 comes close to and separates from each other. The first engagingportion 122 including the above configuration can mutually engage thefirst engaging protrusion 120 provided on the inner tube 104.

As illustrated in FIGS. 14 and 15, when the inner tube 104 relativelymoves forward to a predetermined position with respect to the outer tube106, the first engaging portion 122 and the first engaging protrusion120 engage with each other. Specifically, the first engaging portion 122gets over the pair of pawls 123 and the pair of pawls 123 hooks on bothsides of a base end of the first engaging protrusion 120. A state wherethe first engaging portion 122 and the first engaging protrusion 120have engaged with each other, helps prevent a relative movement in theaxial direction between the inner tube 104 and the outer tube 106.Therefore, the inner tube 104 is prevented from coming off the outertube 106 to the leading end side. In addition, the inner tube 104 isprevented from moving backward into the outer tube 106.

In this manner, a first locking mechanism 126 for preventing relativedisplacement in the axial direction between the inner tube 104 and theouter tube 106 in a state where the protector 90 has covered theneedlepoint 87, can include the first engaging portion 122 and the firstengaging protrusion 120. Note that even in a case where bending stresshas acted on the inner tube 104 and the outer tube 106, engaging actionbetween the rail protrusions 110 provided on an outer surface of theinner tube 104 and the rail grooves 117 provided on the inner surface ofthe outer tube 106, helps prevent the first engaging protrusion 120 fromcoming off the first engaging portion 122. Accordingly, the function ofthe first locking mechanism 126 can be preferably retained.

As illustrated in FIGS. 14 and 15, an outer surface of a base endportion of the outer tube 106 can include a second engaging protrusion128 protruding outward (downward in the illustrated example) providedthereon. Meanwhile, the needle hub 88 (specifically, the extensionportion 100) can include a second passage 129 extending in the axialdirection and allowing displacement in the axial direction of the secondengaging protrusion 128 provided on the outer tube 106, and a secondengaging portion 130 disposed on the side of a leading end of the secondpassage 129, provided thereon. The second passage 129 extends to a baseend surface of the needle hub 88. In the initial state of the catheterassembly 10B, the second engaging protrusion 128 is positioned at a baseend of the second passage 129. According to the present embodiment, thesecond passage 129 is a hole passing through the inside and the outsideof the needle hub 88, but may be a groove provided on an inner surfaceof the needle hub 88.

The second engaging portion 130 has a pair of pawls 131 protruding intothe second passage 129. A slit long hole 132 extending in the axialdirection of the needle hub 88, is provided on each of the left andright outsides of the pair of pawls 131. Accordingly, the pair of pawls131 is elastically deformable in directions in which the pair of pawls131 comes close to and separates from each other. The second engagingportion 130 including the above configuration can mutually engage thesecond engaging protrusion 128 provided on the inner tube 104.

As illustrated in FIGS. 14 and 15, when the outer tube 106 relativelymoves forward to a predetermined position with respect to the needle hub88, the second engaging portion 130 and the second engaging protrusion128 engage with each other. Specifically, the second engaging protrusion128 gets over the pair of pawls 131 and the pair of pawls 131 hooks onboth sides of a base end of the second engaging protrusion 128. A statewhere the second engaging portion 130 and the second engaging protrusion128 have engaged with each other, helps prevent relative displacement inthe axial direction between the outer tube 106 and the needle hub 88.Therefore, the outer tube 106 is prevented from coming off the needlehub 88. In addition, the outer tube 106 is prevented from movingbackward into the needle hub 88.

In this manner, a second locking mechanism 134 for preventing therelative movement in the axial direction between the outer tube 106 andthe needle hub 88 in a state where the protector 90 has covered theneedlepoint 87, can include the second engaging portion 130 and thesecond engaging protrusion 128. Note that even in a case where bendingstress has acted on the outer tube 106 and the needle hub 88, engagingaction between the rail protrusions 118 provided on an outer surface ofthe outer tube 106 and the rail grooves 102 provided on the innersurface of the needle hub 88, helps prevent the second engagingprotrusion 128 from coming off the second engaging portion 130.Accordingly, the function of the second locking mechanism 134 can bepreferably retained.

As illustrated in FIG. 14, the first locking mechanism 126 and thesecond locking mechanism 134 are disposed so as to be shifted to eachother in a circumferential direction.

The needle support portion 20 according to the second embodiment has aconfiguration similar to that of the needle support portion 20 accordingto the first embodiment. That is, in the initial state of the catheterassembly 10B, the needle support portion 20 supports the inner needle 86through the catheter 82 on the leading end side beyond the catheter hub84. The needle support portion 20 can be movable with respect to theneedle hub 88 in order to change from a first state of supporting theinner needle 86 to a second state of releasing the support with respectto the inner needle 86 and allowing the catheter hub 84 to pass. In theinitial state, a coupling portion between each of the pair of supportarms 42 and the extension portion 100, is positioned on the leading endside beyond the base end of the catheter hub 84. A leading end of theneedle hub 88 (a leading end of the extension portion 100) and each ofthe support arms 42 are coupled so as to be rotatable through a hingestructure 48 similar to that according to the first embodiment.

A restraining portion 44 according to the second embodiment has aconfiguration similar to that of the restraining portion 44 according tothe first embodiment. The restraining portion 44 is pressed by thecatheter hub 84 in accordance with a forward movement of the catheterhub 84 so that the restraint with respect to the pair of the supportarms 42 is released.

Note that the respective members in the catheter assembly 10B accordingto the second embodiment, having the same terms as those in the catheterassembly 10A according to the first embodiment, include the materialsexemplified as constituent materials of those of the catheter assembly10A.

The catheter assembly 10B according to the second embodiment isbasically constituted as described above. Functions and effects of thecatheter assembly 10B will be described below.

As illustrated in FIGS. 11 and 13, the catheter assembly 10B in theinitial state is in a state to be described below. The inner needle 86has been inserted into the catheter 82 and the needlepoint 87 hasprotruded from the leading end of the catheter 82 by the predeterminedlength. The leading end fitting portion 108 of the inner tube 104 hasbeen inserted into the base end of the catheter hub 84. The outer tube106 has maximally moved to the leading end side in a movable range withrespect to the inner tube 104. The catheter 82 and the inner needle 86have been exposed from the leading end of the needle hub 88, and thecatheter hub 84 and the protector 90 have been housed in the needle hub88. The protector 90 is positioned on the base end side in the needlehub 88. The restraining portion 44 has been positioned at the backwardposition in a movable range. The pair of support arms 42 has beenrestrained in the closed state by the restraining portion 44. The innerneedle 86 has been held by the pair of support arms 42 in the closedstate through the catheter 82.

In the use of the catheter assembly 10B, a user (for example, a medicaldoctor or a nurse) grips the needle hub 88 and punctures a blood vesselof a patient with the catheter 82 and the inner needle 86. In this case,the inner needle 86 has been supported by a support hole 54 formedbetween the pair of support arms 42 that has been closed, through thecatheter 82, so that the deflection of the inner needle 86 is inhibitedupon the puncture. Accordingly, a stable puncture can be performed.

After the puncture, a finger hooks the pair of wings 94 protruding fromthe needle hub 88, and presses the pair of wings 94 in the leading enddirection. Accordingly, the catheter hub 84 and the catheter 82 thathave been coupled to the pair of wings 94, move in the leading enddirection with respect to the needle hub 88. Thus, an insertion lengthof the catheter 82 into the blood vessel increases. Meanwhile, theprotector 90 coupled to the catheter hub 84 also moves forward in theneedle hub 88 in accordance with the forward movement operation of thewings 94.

As illustrated in FIGS. 16A and 16B, the catheter hub 84 presses therestraining portion 44 in the leading end direction in accordance withthe forward movement of the catheter hub 84. Accordingly, therestraining portion 44 moves in the leading end direction with respectto the pair of support arms 42, and the second restraining protrusion 58b separates from the second engaging groove 56 b. The second restrainingprotrusion 58 b separates from the second engaging groove 56 b so thatthe restraint of the restraining portion 44 with respect to the pair ofsupport arms 42 is released and the pair of support arms 42 becomesexpansible. After that, the pair of support arms 42 is pressed from therear side by the catheter hub 84 and expands in accordance with afurther forward movement of the catheter hub 84.

After the catheter 82 has been inserted into the blood vessel by apredetermined length, the needle hub 88 is next pulled in the base enddirection in a state where a position of the catheter member 98 has beenheld. Accordingly, the inner needle 86 moves in the base end directionin the catheter 82, the catheter hub 84, and the protector 90. In thiscase, since the leading end fitting portion 108 of the inner tube 104 ofthe protector 90 and the catheter hub 84 have fitted to each other dueto predetermined fitting force, the protector 90 extends in accordancewith the backward movement of the needle hub 88. Specifically, the innertube 104 relatively moves to the side of a leading end of the outer tube106 and the outer tube 106 also relatively moves to the side of theleading end of the needle hub 88. After a while, a state where theprotector 90 has maximally extended is acquired (refer to FIGS. 17A and17B). During a process during which the protector 90 maximally extends,the inner needle 86 is evulsed from the catheter 82. In addition, theinner needle 86 is housed in the protector 90 with the needlepoint 87.

In a state where the protector 90 has maximally extended, as illustratedin FIGS. 14 and 15, a function of the first locking mechanism 126 helpsprevent the relative movement in the axial direction between the innertube 104 and the outer tube 106. In addition, a function of the secondlocking mechanism 134 helps prevent the relative movement in the axialdirection between the outer tube 106 and the needle hub 88.

Specifically, in the first locking mechanism 126, since the firstengaging protrusion 120 has been positioned at the maximum leading endposition of the first passage 121, the inner tube 104 cannot move anyfurther in the leading end direction with respect to the outer tube 106.In the first locking mechanism 126, since the first engaging protrusion120 and the first engaging portion 122 has engaged with each other, theinner tube 104 cannot move in the base end direction with respect to theouter tube 106.

In the second locking mechanism 134, since the second engagingprotrusion 128 has been positioned at the maximum leading end positionof the second passage 129, the outer tube 106 cannot move any further inthe leading end direction with respect to the needle hub 88. In thesecond locking mechanism 134, since the second engaging protrusion 128and the second engaging portion 130 have engaged with each other, theouter tube 106 cannot move in the base end direction with respect to theneedle hub 88.

During a process during which the catheter assembly 10B is transferredfrom a state in FIG. 16A to a state in FIG. 17A, the pair of supportarms 42 is pressed from the rear side by the catheter hub 84 so as toexpand and allow movements of the catheter hub 84 and the protector 90with respect to the needle hub 88 (refer to FIG. 17B). In this manner,the needle support portion 20 supports the inner needle 86 in theinitial state and inhibits the deflection of the inner needle 86 uponthe puncture. Meanwhile, after the puncture, the pair of support arms 42opens so as to prevent interference with the catheter hub 84 and theprotector 90.

After the protector 90 has maximally extended, when the needle hub 88 isfurther pulled in the base end direction with respect to the cathetermember 98, as illustrated in FIG. 18, the fit between the catheter hub84 and the leading end fitting portion 108 of the inner tube 104 comesoff. Accordingly, a state where the protector 90 has completelyseparated from the catheter member 98 and only the catheter member 98out of the catheter assembly 10B has been detained on the side of thepatient, can be acquired.

After the catheter member 98 and the protector 90 have separated fromeach other, the pair of wings 94 provided on the catheter hub 84 expandsin the left and right direction. The pair of wings 94 is fixed to skinof the patient with a tape or the like so as to fix the catheter hub 84.A connector of a transfusion tube, not illustrated, can be coupled tothe side of the base end of the catheter hub 84, and supply of atransfusion material (a medical fluid) to the patient through thetransfusion tube can be performed.

As described above, the catheter assembly 10B according to the secondembodiment is capable of inhibiting the deflection of the inner needle86 upon a puncture and performing a stable puncture since the pair ofsupport arms 42 supports the inner needle 86 upon the puncture.According to the second embodiment, other respective constituentportions shared with the first embodiment acquire functions and effectssimilar to those according to the first embodiment.

According to the second embodiment, in the initial state, the catheterhub 84 has been housed in the needle hub 88 (refer to FIG. 11).Accordingly, an exposure length of the inner needle 86 from the needlehub 88 included in the housing can be shortened in comparison to aconventional catheter assembly having a protector. Therefore, an entirelength of the catheter assembly 10B in the initial state, namely, alength from the base end of the needle hub 88 to a leading end of theinner needle 86 can be made shorter than a conventional catheterassembly having a protector. Accordingly, excellent storage due to itscompactness can be acquired and the puncture operation can be performedrelatively easily. Since the exposure length of the inner needle 86 fromthe needle hub 88 is short, the protector 90 may be also made to beshort. Accordingly, an entire product length even in a state where theprotector 90 has covered the needlepoint 87 (a needlepoint protectingstate), can be relatively short. Therefore, the waste is compact, anddisposal is relatively easy to perform.

Furthermore, according to the second embodiment, since the pair of wings94 functions as the operating portion for the catheter hub 84 in theinitial state, there is no need for providing an exclusive operatingportion to the catheter hub 84. Thus, the configuration can berelatively simplified.

Note that, the catheter assembly 10B may adopt the needle supportportions 20 a to 20 c illustrated in FIGS. 7A to 8, respectively,instead of the needle support portion 20. The catheter assembly 10B mayadopt the hinge structures 48 a and 48 b illustrated in FIGS. 9A to 9Cinstead of the hinge structure 48. The catheter assembly 10B may adoptsupport holes 54 a to 54 d illustrated in FIGS. 10A to 10D,respectively, instead of the support hole 54.

In the above configuration, the catheter hub 84 presses the restrainingportion 44 so that the restraint with respect to the pair of supportarms 42 is released. Instead of this type of configuration, the wings 94may press the restraining portion 44, and the restraint with respect tothe pair of support arms 42 may be released. Alternatively, the catheterassembly 10B may further include a guide wire G inserted into the innerneedle 86, and a guide wire operating portion 64 for operating the guidewire G, the guide wire operating portion 64 being coupled to the guidewire G (refer to FIG. 13). In this case, the guide wire operatingportion 64 may press the restraining portion 44 in accordance with aforward movement of the guide wire operating portion 64. Thus, therestraint with respect to the pair of support arms 42 may be released.

FIG. 19 is a perspective view of a catheter assembly 10C according to athird embodiment of the present disclosure. FIG. 20 is an explodedperspective view of the catheter assembly 10C. FIG. 21 is a partiallyomitted longitudinal-sectional view of the catheter assembly 10C. Notethat, in the catheter assembly 10C according to the third embodiment,elements having functions and effects the same as or similar to those ofthe catheter assembly 10B according to the second embodiment, aredenoted with the same reference signs, and the duplicate descriptionsthereof will be omitted.

The catheter assembly 10C can include a tubular catheter 152 havingflexibility, a catheter hub 154 coupled to the side of a base end of thecatheter 152, a tubular inner needle 156 having a sharp needlepoint 157on a leading end and insertable into the inside of the catheter 152, aneedle hub 158 coupled to the inner needle 156, a protector 90 thatcovers the needlepoint 157 of the inner needle 156 when the inner needle156 is evulsed, and a needle support portion 172 for inhibitingdeflection of the inner needle 156 upon a puncture.

A user (for example, a medical doctor or a nurse) grips and operates theneedle hub 158 so that a leading end portion of the catheter assembly10C punctures a blood vessel of a patient. The catheter assembly 10C hasa double tubular structure in which the inner needle 156 has beeninserted into the catheter 152 and the inner needle 156 has protrudedfrom a leading end of the catheter 152 by a predetermined length in aninitial state before use (before a puncture to the patient). In theinitial state of the catheter assembly 10C, the side of a base end ofthe catheter hub 154 and the side of a leading end of the needle hub 158have been coupled through a protector 90.

The catheter assembly 10C in the initial state can include one assemblyhaving the double tubular structure of the catheter 152 and the innerneedle 156, the catheter hub 154, the protector 90, and the needle hub158 combined, and is integrally operable.

The catheter 152 according to the third embodiment is longer than thecatheters 12 and 82 according to the first and second embodiments,respectively. The catheter 152 may be used as a catheter, for example, acentral venous catheter, a PICC, or a midline catheter, longer than aperipheral venous catheter in length. Note that the catheter 152 may beused as the peripheral venous catheter.

The hollow cylindrical catheter hub 154 is coupled and fixed to a baseend of the catheter 152. A flange portion 155 protruding outward andextending in a circumferential direction, is provided on a base end ofthe catheter hub 154.

The catheter hub 154 is provided with a hub operating portion 160 foroperating the catheter hub 154. In the initial state of the catheterassembly 10C, at least a part of the hub operating portion 160 has beenexposed from the needle hub 158. Specifically, in the initial state, thehub operating portion 160 extends along the inner needle 156 and thecatheter hub 154. In addition, a base end portion is coupled to thecatheter hub 154, and a leading end portion is exposed on the side ofthe leading end of the needle hub 158.

The hub operating portion 160 has a long main body portion 161 and a tab162 to be hooked by a finger, the tab 162 being provided at a leadingend of the main body portion 161. The tab 162 protrudes upward from theleading end of the main body portion 161.

The hub operating portion 160 is coupled to the catheter hub 154 so asto be rotatable. In the present illustrated example, a supportprotrusion 163 protruding outward is provided on an outer surface oneach of the left and right sides of the catheter hub 154. Each of thesupport protrusions 163 extends in an upper and lower direction.Meanwhile, a base end portion of the main body portion 161 can include apair of coupling pieces 164 each having a coupling groove 165 and facingeach other on the left and right sides, provided thereon.

As illustrated in FIG. 22A, each of the coupling grooves 165 can includea first groove 165 a for engagement and a second groove 165 b forseparation having a groove width narrower than the first groove 165 a,extending from the first groove 165 a in a base end direction, andreaching a base end surface of the coupling piece 164. The groove widthW2 of the second grooves 165 b is slightly larger than a width W1 of thesupport protrusions 163 (refer to FIG. 22B). Each of the supportprotrusions 163 provided to the catheter hub 154 is inserted into eachof the first grooves 165 a provided to the hub operating portion 160.Accordingly, the hub operating portion 160 has the support protrusions163 as axial portions and is supported so as to be rotatable withrespect to the catheter hub 154. In the initial state, the hub operatingportion 160 is substantially parallel to the catheter 152 and the innerneedle 156, and each of the support protrusions 163 engages with each ofthe first grooves 165 a. Thus, the hub operating portion 160 can beprevented from separating from the catheter hub 154.

As illustrated in FIG. 22B, since extending directions of the supportprotrusions 163 and the second grooves 165 b become the same at aposition at which the hub operating portion 160 is substantiallyperpendicular to an axial direction of the catheter hub 154, the huboperating portion 160 is separable from the catheter hub 154. Note thata constituent material of the hub operating portion 160 is notparticularly limited, and may be the same as a constituent material ofthe catheter hub 154, for example.

Hereinafter, a member including the catheter 152, the catheter hub 154,and the hub operating portion 160, will be referred to as a “cathetermember 168”.

As illustrated in FIG. 21, the inner needle 156 is formed sufficientlylonger than the catheter 152. In the initial state of the catheterassembly 10C, the needlepoint 157 protrudes from a leading end openingof the catheter 152 by a predetermined length. The inner needle 156according to the third embodiment is longer than the inner needles 16and 86 according to the first and second embodiments, respectively.

In the initial state of the catheter assembly 10C, the inner needle 156has a midway part in the longitudinal direction inserted into the insideof the catheter hub 154, and has the side of the base end held insidethe needle hub 158.

The needle hub 158 has an inner needle holding portion 101 holding thebase end of the inner needle 156, and an extension portion 170protruding in a leading end direction beyond the catheter hub 154. Theextension portion 170 is included in a housing that houses the catheterhub 154 and the protector 90 in the initial state. In the initial state,a coupling portion between each of the pair of support arms 173 and theextension portion 170, is positioned on the leading end side beyond thebase end of the catheter hub 154. The extension portion 170 according tothe third embodiment is longer than the extension portion 100 accordingto the second embodiment.

In the initial state of the catheter assembly 10C, the catheter 152 andthe inner needle 156 are exposed from the leading end of the needle hub158, and the catheter hub 154 and the protector 90 are housed in theneedle hub 158. As a result, the leading end of the needle hub 158protrudes to a midway of the catheter 152. According to the presentembodiment, a position of the base end of the catheter hub 154 ispositioned on the base end side beyond a position of the center in anaxial direction of the needle hub 158, and the leading end of the needlehub 158 is positioned on the leading end side beyond a position of thecenter in a longitudinal direction of the catheter 152.

In the initial state of the catheter assembly 10C, a majority of the huboperating portion 160 is housed in the needle hub 158, and the leadingend portion of the hub operating portion 160 (tab 162) is exposed on theleading end side beyond the leading end of the needle hub 158.

The protector 90 houses the inner needle 156 upon evulsion of the innerneedle 156 from the catheter 152 so as to cover the needlepoint 157 ofthe inner needle 156. The protector 90 according to the third embodimenthas a configuration similar to that of the protector 90 according to thesecond embodiment, and has an inner tube 104 and an outer tube 106. Inthe initial state, a leading end fitting portion 108 of the inner tube104 fits to the inside of the base end of the catheter hub 154. Upon anevulsion operation of the inner needle 156 from the catheter 152, theprotector 90 extends with the needle hub 158 so as to cover an entirelength of the inner needle 156 (refer to FIG. 26). Note that thecatheter assembly 10C also can include the first locking mechanism 126and the second locking mechanism 134 illustrated in FIG. 15.

As illustrated in FIGS. 19 and 21, the needle support portion 172supports the inner needle 156 through a catheter 152 on the leading endside beyond the catheter hub 154 in the initial state. The needlesupport portion 172 is provided movable with respect to the needle hub158 in order to change from a first state of supporting the inner needle156 to a second state of releasing the support with respect to the innerneedle 156 and allowing the catheter hub 154 to pass.

According to the third embodiment, specifically, the needle supportportion 172 has the pair of support arms 173 openable and closeable anda restraining portion 176 capable of restraining the pair of supportarms 173 in a closed state and also releasing the restraint.

The pair of support arms 173 is rotatably coupled to the extensionportion 170 through a pair of support pins 43. In the initial state, thecoupling portion between each of the pair of support arms 173 and theextension portion 170, is positioned on the leading end side beyond thebase end of the catheter hub 154.

In the present illustrated example, each of the pair of support pins 43has an axis in an upper and lower direction. The pair of support arms173 supported by the pair of support pins 43 is openable and closeablein a left and right direction. One of the support arms 173 has a bendingengaging groove 174 a provided thereon and the other has a bendingengaging groove 174 b provided thereon when viewed from the front sidein the closed state. Each of the engaging grooves 174 a and 174 b passesthrough each of the support arms 173 in a longitudinal direction.

In the present illustrated example, the one engaging groove 174 a(hereinafter, referred to as a “first engaging groove 174 a”) and theother engaging groove 174 b (hereinafter, referred to as a “secondengaging groove 174 b) both bend downward. Note that the first engaginggroove 174 a and the second engaging groove 174 b both may bend upward.Alternatively, one may bend upward and the other may bend downward.

A configuration of the pair of support arms 173 according to the thirdembodiment is similar to the pair of support arms 42 according to thefirst embodiment except the first engaging groove 174 a and the secondengaging groove 174 b. The leading end of the needle hub 158 (a leadingend of the extension portion 170) and each of the support arms 173 arecoupled so as to be rotatable through a hinge structure 48 the same asin the first embodiment.

The restraining portion 176 is slidable with respect to the pair ofsupport arms 173, and is formed as a part of the above hub operatingportion 160. The restraining portion 176 moves forward in accordancewith a forward movement of the hub operating portion 160 so that therestraint with respect to the pair of support arms 173 is released.

Specifically, the restraining portion 176 is provided at a leading endof the main body portion 161 of the hub operating portion 160. FIG. 23is a cross-sectional view taken along line XXIII-XXIII of FIG. 21. Asillustrated in FIG. 23, the restraining portion 176 has a firstrestraining protrusion 177 a engaging with the first engaging groove 174a so as to be slidable and a second restraining protrusion 177 bengaging with the second engaging groove 174 b so as to be slidable.

In the present illustrated example, the first restraining protrusion 177a and the second restraining protrusion 177 b protrude in the samedirection so as to adapt to shapes of the first engaging groove 174 aand the second engaging groove 174 b provided on the pair of supportarms 173, respectively. When the restraining portion 176 is positionedat an initial position (backward position), the first restrainingprotrusion 177 a and the second restraining protrusion 177 b of therestraining portion 176 engage with the first engaging groove 174 a andthe second engaging groove 174 b of the pair of support arms 173,respectively. Thus, the pair of support arms 173 is restrained in aclosed state.

In accordance with a movement of the restraining portion 176 in theleading end direction, the first restraining protrusion 177 a and thesecond restraining protrusion 177 b separate from the first engaginggroove 174 a and the second engaging groove 174 b of the pair of supportarms 173 in the leading end direction, respectively. When the firstrestraining protrusion 177 a and the second restraining protrusion 177 bseparate from the first engaging groove 174 a and the second engaginggroove 174 b, respectively, the restraint of the restraining portion 176with respect to the pair of support arms 173 is released. Then, the pairof support arms 173 becomes expansible.

As illustrated in FIGS. 19 and 20, the hub operating portion 160 caninclude a protrusion for expansion 178 for opening the pair of supportarms 173, provided slightly on the base end side beyond the restrainingportion 176. The protrusion for expansion 178 is formed so as to betapered and be triangular in the present illustrated example.

Note that the respective members in the catheter assembly 10C accordingto the third embodiment, having the same terms as those in the catheterassemblies 10A and 10B according to the first and second embodiments,include the materials exemplified as constituent materials of those ofthe catheter assemblies 10A and 10B.

The catheter assembly 10C according to the third embodiment is basicallyconstituted as described above. Functions and effects of the catheterassembly 10C will be described below.

As illustrated in FIGS. 19 and 21, the catheter assembly 10C in theinitial state is in a state to be described below. The inner needle 156has been inserted into the catheter 152 and the needlepoint 157 hasprotruded from the leading end of the catheter 152 by the predeterminedlength. The leading end fitting portion 108 of the inner tube 104 hasbeen inserted into the base end of the catheter hub 154. The outer tube106 has maximally moved to the leading end side in a movable range withrespect to the inner tube 104. The catheter 152 and the inner needle 156have been exposed from the leading end of the needle hub 158, and thecatheter hub 154 and the protector 90 have been housed in the needle hub158. The protector 90 is positioned on the base end side in the needlehub 158. The restraining portion 176 has been positioned at the backwardposition in a movable range. The pair of support arms 173 has beenrestrained in the closed state by the restraining portion 176. The innerneedle 156 has been held by the pair of support arms 173 in the closedstate through the catheter 152.

In the use of the catheter assembly 10C, a user (for example, a medicaldoctor or a nurse) grips the needle hub 158 and punctures a blood vesselof a patient with the catheter 152 and the inner needle 156. In thiscase, a portion close to the leading end of the needle hub 158 isgripped so that the needlepoint 157 becomes stable and the punctureoperation is performed relatively easily. Upon the puncture, the pair ofsupport arms 173 that has been closed supports the inner needle 156through the catheter 152. Thus, the deflection of the inner needle 156upon the puncture is inhibited or prevented. Accordingly, a stablepuncture can be performed.

After the puncture, a finger hooks the tab 162 provided at a leading endof the hub operating portion 160, and presses the tab 162 in the leadingend direction. In this case, a finger of a hand (for example, an indexfinger) that has gripped the part close to the leading end of the needlehub 158, can operate the tab 162. Thus, transition from the operation ofthe puncture to the operation of the tab 162 is promptly performed.

When the tab 162 is pressed in the leading end portion, the restrainingportion 176 provided on the hub operating portion 160 moves in theleading end direction with respect to the pair of support arms 173.Then, the first restraining protrusion 177 a and the second restrainingprotrusion 177 b separate from the first engaging groove 174 a and thesecond engaging groove 174 b, respectively. Due to the separation, therestraint of the restraining portion 176 with respect to the pair ofsupport arms 173 is released. Then, the pair of support arms 173 becomesexpansible.

As illustrated in FIGS. 24A and 24B, when the hub operating portion 160further moves forward, the pair of support arms 173 is pressed from therear side by the protrusion for expansion 178 so as to expand. In thiscase, the leading end portion of the hub operating portion 160 isflexible at a part of a thin-walled portion 161 a. Thus, the leading endof the hub operating portion 160 can be prevented from interfering withskin of the patient.

Next, as illustrated in FIG. 25, when the hub operating portion 160further moves forward, the catheter hub 154 and catheter 152 that havebeen coupled to the hub operating portion 160 further move in theleading end direction with respect to the needle hub 158. Thus, aninsertion length of the catheter 152 into the blood vessel increases.Meanwhile, the protector 90 coupled to the catheter hub 154 also movesforward in the needle hub 158 in accordance with the forward movement ofthe hub operating portion 160.

When the catheter 152 has been inserted into the blood vessel by apredetermined length, next, the needle hub 158 is pulled in the base enddirection with respect to the catheter member 168. Accordingly, theinner needle 156 moves in the base end direction in the catheter 152,the catheter hub 154, and the protector 90. In this case, since theleading end fitting portion 108 of the inner tube 104 of the protector90 and the catheter hub 154 have fitted to each other due topredetermined fitting force, the protector 90 extends in accordance withthe backward movement of the needle hub 158. Specifically, the innertube 104 moves to the side of a leading end of the outer tube 106. Inaddition, the outer tube 106 moves to the side of the leading end of theneedle hub 158. Accordingly, a state where the protector 90 hasmaximally extended, is acquired (refer to FIG. 26). During a processduring which the protector 90 maximally extends, the inner needle 156 isevulsed from the catheter 152 and the inner needle 156 is also housed inthe protector 90 with the needlepoint 157.

In a state where the protector 90 has maximally extended, a function ofthe first locking mechanism 126 prevents movements in the axialdirection of the inner tube 104 and the outer tube 106. In addition, afunction of the second locking mechanism 134 prevents movements in theaxial direction of the outer tube 106 and the needle hub 158.

After the protector 90 has maximally extended, when the needle hub 158is further pulled in the base end direction with respect to the cathetermember 168, as illustrated in FIG. 27, the fit between the catheter hub154 and the leading end fitting portion 108 of the inner tube 104 comesoff. Accordingly, a state where the protector 90 has completelyseparated from the catheter member 168 and only the catheter member 168out of the catheter assembly 10C has been detained on the side of thepatient, is acquired.

After the catheter member 168 and the protector 90 have separated fromeach other, the hub operating portion 160 separates from the catheterhub 154. Specifically, in a state where the hub operating portion 160has risen so as to be in a position substantially perpendicular to thecatheter hub 154, the hub operating portion 160 is pulled upward so thatthe hub operating portion 160 separates from the catheter hub 154 (referto FIG. 22B). After that, the catheter hub 154 is fixed to the skin ofthe patient with a dressing material or a tape. A connector of atransfusion tube, not illustrated, is coupled to the side of the baseend of the catheter hub 154, and supply of a transfusion material (amedical fluid) to the patient through the transfusion tube is performed.

As described above, the catheter assembly 10C according to the thirdembodiment is capable of inhibiting the deflection of the inner needle156 upon a puncture and performing a stable puncture since the pair ofsupport arms 173 supports the inner needle 156 upon the puncture as inthe first and second embodiments. As in the second embodiment, since thecatheter hub 154 has been housed in the needle hub 158 in the initialstate, an entire product length can be shortened in both of the initialstate and the needlepoint protecting state due to the protector 90.According to the third embodiment, other respective constituent portionsshared with the first and second embodiments acquire functions andeffects similar to those according to the first and second embodiments.

According to the third embodiment, in the initial state, the huboperating portion 160 extends along the inner needle 156 and thecatheter hub 154. In addition, the base end portion is coupled to thecatheter hub 154 and the leading end portion is exposed on the side ofthe leading end of the needle hub 158. With this configuration, aportion of the hub operating portion 160 that has been exposed on theside of the leading end of the needle hub 158 is touched so that theoperation with respect to the hub operating portion 160 can beperformed. Thus, the same hand that grips the side of the leading end ofthe needle hub 158 upon a puncture, can operate the hub operatingportion 160. Accordingly, the same hand can perform the punctureoperation and the forward movement operation of the catheter 152. Thus,excellent operability can be acquired.

According to the third embodiment, the restraining portion 176 isprovided as a part of the hub operating portion 160, and the restraintwith respect to the pair of support arms 173 is released upon theforward movement of the hub operating portion 160. With thisconfiguration, the restraint with respect to the pair of support arms173 is automatically released in response to the forward movement of thecatheter hub 154 based on the operation with respect to the huboperating portion 160. Thus, there is no need for an independent releaseoperation, and excellent operability is acquired.

Note that the catheter assembly 10C may adopt the support arms 65, 66,and 68 illustrated in FIGS. 7A to 8, respectively, instead of thesupport arms 173. The catheter assembly 10C may adopt the hingestructures 48 a and 48 b illustrated in FIGS. 9A to 9C instead of thehinge structure 48. The catheter assembly 10C may adopt the supportholes 54 a to 54 d illustrated in FIGS. 10A to 10D, respectively,instead of the support hole 54.

The catheter assembly 10C may further include a guide wire G insertedinto the inner needle 156, and a guide wire operating portion 150 foroperating the guide wire G, the guide wire operating portion 150 beingcoupled to the guide wire G (refer to FIG. 21). In this case, therestraining portion 176 may be provided as a part of the guide wireoperating portion 150. In accordance with a forward movement of theguide wire operating portion 150, the guide wire operating portion 150may press the restraining portion 176 so that the restraint with respectto the pair of support arms 173 may be released.

The detailed description above describes a catheter assembly. Theinvention is not limited, however, to the precise embodiments andvariations described. Various changes, modifications and equivalents caneffected by one skilled in the art without departing from the spirit andscope of the invention as defined in the accompanying claims. It isexpressly intended that all such changes, modifications and equivalentswhich fall within the scope of the claims are embraced by the claims.

What is claimed is:
 1. A catheter assembly comprising: a catheter; acatheter hub fixed to a base end portion of the catheter; an innerneedle having a needlepoint, inserted into the catheter; a needle hubcoupled to the inner needle; and a needle support portion for supportingthe inner needle through the catheter on a leading end side beyond thecatheter hub, wherein the needle support portion has a pair of supportarms openable and closeable in a left and right direction, and arestraining portion capable of restraining the pair of support arms in aclosed state and releasing a restraint of the pair of support arms, theneedle hub having an extension portion extending in a leading enddirection beyond the catheter hub, the pair of support arms beinglaterally disposed between the restraining portion.
 2. The catheterassembly according to claim 1, wherein the restraining portion ismovable with respect to the pair of support arms, and in accordance witha forward movement of the catheter hub or a forward movement of a guidewire operating portion for operating a guide wire inserted into theinner needle, a hub operating portion provided on the catheter hub, orthe guide wire operating portion presses the restraining portion so asto release the restraint with respect to the pair of support arms. 3.The catheter assembly according to claim 1, wherein the restrainingportion has a frame shape configured to at least partially surround aleading end portion of the pair of support arms.
 4. The catheterassembly according to claim 2, wherein the hub operating portion iscoupled to the restraining portion.
 5. The catheter assembly accordingto claim 1, further comprising: a step portion on a leading lowerportion of each of the pair of support arms.
 6. The catheter assemblyaccording to claim 5, wherein the restraining portion has left and rightinward protruding ends configured to be received within the step portionon the leading lower portion of the each of the pair of support arms. 7.The catheter assembly according to claim 1, wherein the extensionportion and each of the support arms are coupled so as to be rotatablethrough a hinge structure having a first structure and a secondstructure, the first structure is provided on one of the extensionportions and each of the support arms, and has a plurality of couplingpieces facing each other and a recess portion formed between theplurality of coupling pieces, and the second structure is provided onanother of the extension portion and each of the support arms, and has acoupling protruding portion disposed in the recess portion.
 8. Thecatheter assembly according to claim 7, wherein a support hole forsupporting the inner needle is formed between the pair of support armsin the closed state, and a contact surface between the pair of supportarms is shifted in the left and right direction with respect to a centerof the inner needle supported by the support hole.
 9. The catheterassembly according to claim 2, wherein the hub operating portion is atab protruding upward from a leading edge of the catheter hub.
 10. Acatheter assembly comprising: a catheter; a catheter hub fixed to a baseend portion of the catheter; an inner needle having a needlepoint,inserted into the catheter; a needle hub coupled to the inner needle; aneedle support portion for supporting the inner needle through thecatheter on a leading end side beyond the catheter hub, wherein theneedle support portion has a pair of support arms openable and closeablein a left and right direction, and a restraining portion capable ofrestraining the pair of support arms in a closed state and releasing arestraint of the pair of support arms, the needle hub having anextension portion extending in a leading end direction beyond thecatheter hub, an hub operating portion coupled to the catheter hub, andthe pair of support arms being laterally disposed between therestraining portion; and wherein the restraining portion is movable withrespect to the pair of support arms, and a forward movement of the huboperating portion releases the restraint with respect to the pair ofsupport arms.
 11. The catheter assembly according to claim 10, whereinthe restraining portion has a frame shape configured to at leastpartially surround a leading end portion of the pair of support arms.12. The catheter assembly according to claim 10, further comprising: astep portion on a leading lower portion of each of the pair of supportarms; and wherein the restraining portion has left and right inwardprotruding ends configured to be received within the step portion on theleading lower portion of the each of the pair of support arms.
 13. Acatheter assembly comprising: a catheter; a catheter hub configured tobe fixed to a base end portion of the catheter; an inner needle having aneedlepoint configured to be insertable into the catheter; a needle hubconfigured to be coupled to the inner needle; and a needle supportportion configured to support the inner needle through the catheter on aleading end side beyond the catheter hub, wherein the needle supportportion has a pair of openable and closeable support arms, a restrainingportion capable of restraining the pair of openable and closeablesupport arms, the needle hub having an extension portion extending in aleading end direction beyond the catheter hub, and the pair of openableand closeable support arms being laterally disposed between therestraining portion.
 14. The catheter assembly according to claim 1,wherein the restraining portion is movable with respect to the pair ofopenable and closeable support arms, and in accordance with a forwardmovement of the catheter hub, a hub operating portion provided on thecatheter hub presses the restraining portion so as to release therestraining portion with respect to the pair of openable and closeablesupport arms.
 15. The catheter assembly according to claim 13, whereinthe restraining portion is movable with respect to the pair of openableand closeable support arms, and in accordance with a forward movement ofa guide wire operating portion for operating a guide wire inserted intothe inner needle, the guide wire operating portion presses therestraining portion so as to release the restraining portion withrespect to the pair of openable and closeable support arms.
 16. Thecatheter assembly according to claim 13, wherein the restraining portionhas a frame shape configured to at least partially surround a leadingend portion of the pair of openable and closeable support arms.
 17. Thecatheter assembly according to claim 14, wherein the hub operatingportion is coupled to the restraining portion.
 18. The catheter assemblyaccording to claim 13, further comprising: a step portion on a leadinglower portion of each of the pair of openable and closeable supportarms.
 19. The catheter assembly according to claim 18, wherein therestraining portion has inward protruding ends configured to be receivedwithin the step portion on the leading lower portion of the each of thepair of openable and closeable support arms.
 20. The catheter assemblyaccording to claim 13, wherein the extension portion and each of theopenable and closeable support arms are coupled so as to be rotatablethrough a hinge structure having a first structure and a secondstructure, the first structure is provided on one of the extensionportions and each of the openable and closeable support arms, and has aplurality of coupling pieces facing each other and a recess portionformed between the plurality of coupling pieces, and the secondstructure is provided on another of the extension portion and each ofthe openable and closeable support arms, and has a coupling protrudingportion disposed in the recess portion.